Do You, Manual Focus?

[KicknGuitar]

I run around with a DSL and love to snap candid photos. Autofocus is great for when the subject is big enough in my frame, however with manual focus I can just set the distance by reading the focusing ring . . . or so I used to on film lenses. Seems that these autofocus lenses have no markings for distance and such small rings that when I twist an inch, I've focused 20 feet!!!

I'm trying my best with my DSLR lenses, but somehow my focus gets off every now and again. I seem to work much better with manual film lenses.

Which focusing style do you use? Why do you use it over the other?

Cheers.

[KentDub]

I use manual focus when autofocus fails. I also use it when shooting static objects when the camera is on a tripod (Actually I autofocus then switch it over to manual so it dosn't move for multiple exposures).

I've yet to master the circle of confusion and hyperfocal distance (it's confusing! and a lot to memorize... I need a cheat sheet) - but I imagine that you need to use manual focus for those techniques.

My two lenses have distance markings on them -- what lens are you using?

[Colin Southern]

Originally Posted by KicknGuitar

Which focusing style do you use? Why do you use it over the other?

I just use whatever is going to work best at the time:

- For "out and about" shots AF works just fine

- For "before dawn" shots AF doesn't work at all (that's where manual focus with Liveview in 10x mode is handy)

- For "dawn shots" I use AF initially - double-check it - and then switch to manual.

- If I have certain aperture / shutterspeed constraints I might calculate the hyperfocal distance and pace things out.

Hope this helps

[Colin Southern]

Originally Posted by KentDub

I've yet to master the circle of confusion and hyperfocal distance (it's confusing! and a lot to memorize... I need a cheat sheet) - but I imagine that you need to use manual focus for those techniques.

Hyper-focal distances are easy if you put the appropriate app in an iPhone

You can use AF to acquire the initial focus - but - you have to be careful about what you focusing on (ie how far away it is).

[KentDub]

Can't afford an iPhone All the $$ is saving for a new telephoto zoom (You've got me sold on the 70-200 f/2.8 L)

[Bill44]

Originally Posted by Colin Southern

- If I have certain aperture / shutterspeed constraints I might calculate the hyperfocal distance and pace things out.

If you make a habit of this then a Laser Rangefinder/Laser Rule may be of a lot of help. These are a small hand held device that you just point at any object and they read the distance very accurately. Cheap ones are good for about 50-60 feet.

Find an object at the required distance, focus etc etc. saves walking.

[Jim B.]

I use this to help me learn DoF etc.
http://www.dofmaster.com/dofjs.html

The range finder is a nice idea.I have one,I'll give it a go

[KentDub]

Originally Posted by Bill44

If you make a habit of this then a Laser Rangefinder/Laser Rule may be of a lot of help. These are a small hand held device that you just point at any object and they read the distance very accurately. Cheap ones are good for about 50-60 feet.

Find an object at the required distance, focus etc etc. saves walking.

I thought you were supposed to use the ring and window on the lens to focus? Or is this a solution to lenses without the readout windows?

[Colin Southern]

Originally Posted by Bill44

If you make a habit of this then a Laser Rangefinder/Laser Rule may be of a lot of help. These are a small hand held device that you just point at any object and they read the distance very accurately. Cheap ones are good for about 50-60 feet.

Find an object at the required distance, focus etc etc. saves walking.

Hi Bill,

Thanks for that. Can't say I've heard of them (I've only ever heard of the ultra-sonic variety that only really work to the nearest object).

Do you have any links to any by any chance?

[Colin Southern]

Originally Posted by KentDub

I thought you were supposed to use the ring and window on the lens to focus? Or is this a solution to lenses without the readout windows?

It's all well and good to set a distance on the scale ... but ... how do you know what that distance is?

[arith]

Originally Posted by KentDub

I use manual focus when autofocus fails. I also use it when shooting static objects when the camera is on a tripod (Actually I autofocus then switch it over to manual so it dosn't move for multiple exposures).

I've yet to master the circle of confusion and hyperfocal distance (it's confusing! and a lot to memorize... I need a cheat sheet) - but I imagine that you need to use manual focus for those techniques.

My two lenses have distance markings on them -- what lens are you using?

The circle of confusion is fixed for the camera; mine is 0.019mm. The hyperfocal length can be found by the formula f^2/(S*c)+f where f is the focal length S is the f stop and c is the constant (circle of confusion).

All that is important is that you can ignore the added f, and if you double the focal length you quadruple the hyperfocal distance, if you divide the f stop by 2 you double the hyperfocal distance.

If you focus on infinity the hyperfocal distance is the nearest in focus point but generally I don't use any of this but remember the hyperfocal distance for a couple of focal lengths at f8 and then guess.

[Bill44]

Originally Posted by Colin Southern

Hi Bill,

Thanks for that. Can't say I've heard of them (I've only ever heard of the ultra-sonic variety that only really work to the nearest object).

Do you have any links to any by any chance?

Best bet would be a NZ local google, you may find them in a hardware store or builders supplies, they are very popular with carpet salesmen.

This is a very good one, up to 50Metres, but there are cheaper ones available around the A$50 mark. http://www.justtools.com.au/prod1844.htm

[Colin Southern]

Originally Posted by Bill44

Best bet would be a NZ local google, you may find them in a hardware store or builders supplies, they are very popular with carpet salesmen.

This is a very good one, up to 50Metres, but there are cheaper ones available around the A$50 mark. http://www.justtools.com.au/prod1844.htm

Thanks Bill - I found a very nice one for $1800 ...

... and have bought an $80 one (ultrasonic, but "laser guided") - probably won't use it for photography, but I'm forever having issues measuring up walls to hang canvases accurately.

[Davey]

Possible helpful note on the dark hours focus issue, my fuji s5600 struggles in dim light never mind darkness and lcd is often black so manual doesn't work either.

Good solution is a bright torch (a surefire or something is perfect and compact) to "spot" something close by enabling autofocus to work. Another method I have used is place a mobile phone or bright screen pmp at rough distance you want focus at and autofocus or manual focus on it, then focus lock and remove it from the scene and carry on as normal.

Obviously long distance throws this out unless you've got a stupid power hid torch on you which is unlikely.

[Colin Southern]

Originally Posted by Davey

Good solution is a bright torch (a surefire or something is perfect and compact) to "spot" something close by enabling autofocus to work.

I've got a 6x D-Cell Maglite with a 3x High-power LED retro-fit kit (kinda like a car headlight on the end of a metal tube )

In reality it's not too much of an issue though - I'm normally shooting wide-angle at small apertures so DoF is enormous -- just handy to ensure that any foreground objects are correctly focused. 9 times out of 10 adjusting for the smallest light source via liveview in x10 mode works just fine

[Captn Mike]

Originally Posted by KicknGuitar

Which focusing style do you use? Why do you use it over the other?

Well thanks to this post I've spent half my day doing equations to find my camera's circle of confusion and the hyperfocal distance of my 50mm f/1.8. (it's .02mm and 70.2m respectively for those curious).

At any rate, my D5000 doesn't give me the option to autofocus with many lenses (the prime above included). So I call upon my film-acquired skills and manual focus quite a bit. Although, I also find the lens markings misleading. They are a good guideline, but I wouldn't stake my life on it .

But as luck would have it, many of the lenses that don't AF (or when the lens is set MF) do feed distance info to the viewfinder and notify me if I'm focusing too shallow or deep of my subject. As it turns out, I have been comfortable focusing past my subject for sometime (according to this doohickey). This neat TTL feature may help you, kickn if your camera/lens combo supports this.

Still no luck in the dark though.
Hope this helps & Best of luck with your future focus!